Benefit Plans (Assumptions Used) (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension Plan [Member]
Weighted average assumptions used in net periodic benefit cost:
Discount rate	2.70%	2.91%	3.48%
Rate of compensation increase	2.41%	4.00%	4.01%
Long-term rate of return on assets	5.54%	6.71%	6.47%
Weighted average assumptions used in benefit obligations:
Discount rate	2.79%	3.76%
Rate of compensation increase	2.49%	4.01%
Other Postretirement Benefits Plan [Member]
Weighted average assumptions used in net periodic benefit cost:
Discount rate	4.20%	3.45%	3.90%
Weighted average assumptions used in benefit obligations:
Discount rate	3.20%	4.20%